<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@page import="java.awt.image.BufferedImage"%>
<%@page import="java.awt.Graphics2D"%>
<%@page import="java.awt.Color"%>
<%@page import="java.awt.Font"%>
<%@page import="javax.imageio.ImageIO"%>

<%
    int width = 60;
    int height = 18;
// 创建具有可访问图像数据缓冲区的Image
    BufferedImage buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    Graphics2D g = buffImg.createGraphics();

// 创建一个随机数生成器
    Random random = new Random();

    g.setColor(Color.WHITE);
    g.fillRect(0, 0, width, height);

// 创建字体，字体的大小应该根据图片的高度来定
    Font font = new Font("Times New Roman", Font.PLAIN, 18);
// 设置字体
    g.setFont(font);



// 画边框
    g.setColor(Color.BLACK);
   // g.drawRect(0, 0, width - 11, height - 11);

// 随机产生160条干扰线
    g.setColor(Color.LIGHT_GRAY);
    for (int i = 0; i < 155; i++) {
        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int x1 = random.nextInt(12);
        int y1 = random.nextInt(12);
        g.drawLine(x, y, x + x1, y + y1);
    }

// randomCode 用于保存随机产生的验证码
    StringBuffer randomCode = new StringBuffer();
    int red = 0, green = 0, blue = 0;

// 随机产生4位数字的验证码
    for (int i = 0; i < 4; i++) {
// 得到随机产生的验证码数字
        String strRand = String.valueOf(random.nextInt(10));


// 产生随机的颜色分量来构造颜色值
        red = random.nextInt(110);
        green = random.nextInt(50);
        blue = random.nextInt(50);

// 用随机产生的颜色将验证码绘制到图像中
        g.setColor(new Color(red, green, blue));
        g.drawString(strRand, 13 * i + 6, 16);

        randomCode.append(strRand);
    }

// 将四位数字的验证码保存到session中
//HttpSession session1 = request.getSession();
    session.setAttribute("random", randomCode.toString());

// 禁止图像缓存
    response.setHeader("Pragma", "no-cache");
    response.setHeader("Cache-Control", "no-cache");
    response.setDateHeader("Expires", 0);

    response.setContentType("image/jpeg");
// 将图像输出到servlet输出流中
    ServletOutputStream sos = response.getOutputStream();
    ImageIO.write(buffImg, "jpeg", sos);
    sos.close();
//sos = null;
    out.clear();
    out = pageContext.pushBody();
%>